I recently bought a 05 F250 FX4 reg. cab 5.4 with only 32k on it (love the truck) but I have an annoying noise. Best described as a locust sound. the truck has to be warm and it's at about 2k rpm just before it shifts, can't get it make the sound standing still it has to be going down the road, and if it's cool out below 60o or raining it's not there. PLEASE help!

 

My guess would be U joints. With engine off, tranny in park and parking brake applied, crawl under and grip the drive shaft and try to rotate it by hand. Any play whatsoever in a u joint will be a problem.